title: Direct TFIIA-TFIID protein contacts drive budding yeast ribosomal protein gene transcription.
abstract: We have previously shown that yeast TFIID provides coactivator function on the promoters of ribosomal protein-encoding genes (RPGs) by making direct contact with the transactivator repressor activator protein 1 (Rap1). Further, our structural studies of assemblies generated with purified Rap1, TFIID, and TFIIA on RPG enhancer-promoter DNA indicate that Rap1-TFIID interaction induces dramatic conformational rearrangements of enhancer-promoter DNA and TFIID-bound TFIIA. These data indicate a previously unknown yet critical role for yeast TFIIA in the integration of activator-TFIID contacts with promoter conformation and downstream preinitiation complex formation and/or function. Here we describe the use of systematic mutagenesis to define how specific TFIIA contacts contribute to these processes. We have verified that TFIIA is required for RPG transcription in vivo and in vitro, consistent with the existence of a critical Rap1-TFIIA-TFIID interaction network. We also identified essential points of contact for TFIIA and Rap1 within the Rap1 binding domain of the Taf4 subunit of TFIID. These data suggest a mechanism for how interactions between TFIID, TFIIA, and Rap1 contribute to the high rate of transcription initiation seen on RPGs in vivo.
authors.affiliation: Department of Molecular Physiology and Biophysics, School of Medicine, Vanderbilt University, Nashville, Tennessee 37232-0615, USA.
authors.forename: Justin H
authors.initials: JH
authors.lastname: Layer
authors.forename: P Anthony
authors.initials: PA
authors.lastname: Weil
mesh_terms: D004742:Enhancer Elements, Genetic / Q000502:physiology*; D016296:Mutagenesis; D011485:Protein Binding / Q000502:physiology; D012269:Ribosomal Proteins / Q000096:biosynthesis* / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism; D000089804:Shelterin Complex; D035381:TATA-Binding Protein Associated Factors / Q000235:genetics / Q000378:metabolism; D034501:Telomere-Binding Proteins / Q000235:genetics / Q000378:metabolism; D035561:Transcription Factor TFIIA / Q000235:genetics / Q000378:metabolism*; D035362:Transcription Factor TFIID / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D061785:Transcription Initiation, Genetic / Q000502:physiology*
chemical_list: C440829:RAP1 protein, S cerevisiae; D012269:Ribosomal Proteins; D029701:Saccharomyces cerevisiae Proteins; D000089804:Shelterin Complex; C441010:TAF4 protein, S cerevisiae; D035381:TATA-Binding Protein Associated Factors; D034501:Telomere-Binding Proteins; D035561:Transcription Factor TFIIA; D035362:Transcription Factor TFIID; D014157:Transcription Factors
keywords: Gene Expression; RNA; RNA Polymerase II; RNA Polymerase III; Ribosomes; Transcription Coactivators; Transcription Enhancers; Transcription Factors; Transcription Regulation; Yeast